Point of operation saw guard



March 10, 1959 J. M. PETERSON ETAL 2,

POINT OF OPERATION SAW GUARD Filed March 4, 1958 INVENTORS, -M.PaiersDI'L BY A.C.5ervice 7k sowwmw 4 M r h 1 1 J. M. PETERSON ETAL 2,876,810

POINT OF OPERATION SAW GUARD 2 Sheets-Sheet 2 Filed March 4, 1958 Mn 5 Hma M P .1 5 up w B B J Z E. j J A \\\\\\ws Y 2 a B v I a A w a 1 m wWV/////// 4% Av/ ////A, .1 J J 2 w 5 WW J J 5 E K 7 v United StatesPatent POINT OF OPERATION SAW GUARD Joseph M. Peterson and Adellon C.Service, Napa, Calif. Application March 4, 1958, Serial No. 719,177 4Claims. (Cl. 143-159) (Granted under Title 35, U. S. Code (1952), sec.266) The invention described herein may be manufactured and used by orfor the Government for governmental purposes without the payment of anyroyalty thereon.

' This invention relates to a guard for use with a rotary by the eye andtherefore were a disadvantage. Usually,

the saw could only be used to cut in a straight line only as the guardobscured the saw disc.

This disadvantage tempted the operator to dispense with the guard whencutting on an angle, hence expos ing himself to the attendant dangers ofthe unguarded disc. Also, prior art teaches the use of guards that mustbe either very loosely mounted on the motor shaft to cover the upperportion of the disc or else be permanently fixed to the motor housing.In both cases, the work is obscured from the operators vision, and wereclumsy at best.

The present invention provides a saw guard that is light, easy to attachor detach and constructed to cover the point of operation withoutobscuring the line of cut from the vision of the operator either whencutting straight or at an angle. Its construction is simple, consistingof a pair of semi-circular plates, one transparent and the other ofsuitable lightweight material such as aluminum, and spaced by spacingelements. It is quickly clamped on a motor housing by a bracket. One ofthe spacing elements consists of a window disposed at the point ofoperation.

A pair of work-following rollers weight the guard downward to preventthe operator from becoming injured, yet' allows the guard to lift up tofollow the work. This protects the operator from both sides and the edgeof the cutting disc. The guard will easily ride over work pieces to becut, always preventing exposure of the danger points of the disc.

It is therefore a primary object of this invention to provide a sawguard protecting the operator from the attendant dangers present fromuse of a rotary disc saw.

It is another object of the invention to provide a saw guard that allowsthe operator to see the line of cut of the saw.

It is a still further object to provide an inexpensive, yet efficientsaw guard that protects the operator from the saw disc at all timesduring the cutting operation.

It is yet another object to provide a saw guard that can be quicklyattached or detached to a rotary saw.

The exact nature of the invention as well as other ob jects andadvantages thereof will clearly appear from a 7o resilient material suchas rubber.

description of a preferred embodiment as shown in the accompanyingdrawings in which:

Fig. 1 is a side elevation of a guard constructed in accordance with theinvention and protecting a rotary saw disc,

Fig. 2 is a section taken along line 2-2 of Fig. 3 and illustrating thesaw guard as viewed from the other side,

Fig. 3 is a section taken along line 3-3 of Fig. 1 and illustrates theguard mounted on the motor housing,

Fig. 4 is an end elevation of the saw guard,

Fig. 5 is a section taken along line 5-5 of Fig. 1 illustrating a rollerand the manner of mounting same to the guard, and,

Fig. 6 is a section taken along line 6-6 of Fig. 1 and illustrates themounting of the window between the plates.

Referring to the drawing by characters of reference, there is shown inFig. 1 the saw guard of the invention in its position over a saw discand the rollers bearing on 2 is of transparent material, while plate 3is made from a light weight material such as aluminum. Plates 2 and 3are disposed in spaced relation to allow a substantial area for saw disc4, which is mounted to a motor shaft 5 from motor 6 which is adjustablysupported by an arm, etc. (not shown).

When in its cutting position, saw disc 4 rides in a groove 7 (see Fig.3) in a work bench or the like 8.

The plates 2 and 3 are maintained in their spaced, parallel position byan arcuate spacer block 9 and are fastened thereto at theircircumferential edges by suitable fasteners 10.

As previously described, plates 2 and 3 are semi-circular in contour.Spacer block 9 extends from a point at the bottom 11 of the discs toapproximately three fourths of the circumferential distance of theplates, leaving a space 12 for a purpose to be described. In this space12, there is positioned a window generally indicated by 13 to allow thesaw operator to see the line of cut. This window consists of a channelbracket 14 fastened to the inner sides of the plates 2 and 3 by suitablefasteners 15. A fiat piece of transparent material 16 of substantiallyrectangular shape is ed in bracket 14, and serves as the window.

Means for rotatably mounting the hood 1 over the saw 18 erally by 17.The clamp has an elongated shank 18 having an arcuate clamp portion 19integral therewith at its lower end to clamp about a motor housingextension 20. Shank 18 is pivotally mounted on plate 3 by a fastener 21.Means for releasing the bearing for dismounting the guard 1 areprovided, and consists of a bolt and wing nut assembly 22 adjustably anddetachably securing the end of shank 18 to a bracket 23 fastener 24 (seeFig. 2). To provide a bearing surface on plate 3, there is asemi-circular bushing 25 secured in coaxial relation to disc 3 thatcooperates with arcuate portion 19 to maintain the hood 1 in a verticalposition. To permit attachment of the hood 1 over a saw disc having alonger shaft or larger retaining nuts, etc., an extension hood 26 isprovided on plate 2 at an axial location suitable to cover the shaft ornuts.

Means are provided to allow hood 1 to rotate so as to clear the workpiece that is being cut and consists of a pair of rollers, generallyindicated by 27. Each roller is independently mounted coaxially witheach other to the lower forward end of the hood and each roller consistsof a disc 28 (see Fig. 5) having a tire 29 of suitable A disc 30 havinga concentric stub shaft 32 is mounted to the side of each plate 2 and 3by fasteners 31. Anti-friction bearings 33 Ice Patented Mar. 10,1959

slidably mountprovided and comprises a bearing clamp indicatedgenattached to plate 3 by a' rolling and the disc 28 and bearings aresecured on the stub shaft 32 by a screw 34 and washer 35.

The attachment of the guard for use is extremely simple- The bearingbracket 1-7 isdetached: from bracket 24 by loosening wing nut 22 and isrotated to slip about the cylindrical housing extension and the. wingnut 23 is turned until the semi-circular bushing 25 and the arenateportion 19 of the clamp 17 fits loosely about the extension so as topermitrotation of the guard thereabont.

The operation of the guard 1 is entirely automatic andneeds no furtherattention while in use. The rollers 27 provide. enough weight to pullthe guard 1 down over the dangerous part of the saw disc 4' and normallyrest on the floor of the work bench 8.

As. the sawtravels back and forth in the sawing of work pieces (notshown) the hood will rise and fall over the piece tohe cut, therebyalways protecting the operator from the saw disc. The operator canfollow the line of cut with his eye by looking at the saw disc throughthe Window 16 and when cutting on an angle, it may be viewed through thetransparent plate 2.

The clamp 17, being adjustable, allows for attachment of. the; guard toa wide range of, motor housing sizes.

Also: by the hood extension 25, a Wider range of shaft lengths areaccommodated.

From the foregoing, it will be apparent that a novel andsimple yetefficient saw guide has been devised that will give the operator fullvision of the saw cut and full protection from dangers inherent withrotary saw discs at all times during the cutting operation.

Obviously other modifications of the invention may be produced whichwill fall within the bounds of the inventionlas setiforth by theappended claims.

1'. In. a guard for a rotary saw including amotor, an arbor shaft, aconcentric housing attached onsaid'mot'or and a: cutter disc mounted onsaid arbor shaft, a hood adapted to surround the forward and upperportions" of said cutter disc, said hood comprising a pair ofsemicircular plates having axially disposed semi-circular openings' intheir lower edges, a semi-circular bushingfixed along thecircumferential edge of one of said openings in said plates, adapted toride on said concentric housing, an arcuate spacing bar fixed betweensaid plates and adapted to support said plates in a parallel, coaxialrelation, said bar extending a substantial distance about thecircumferential edge of said hood, a U-shaped bracket fixed between saidplates in the forward portion of said hood, a work observation windowsecured in said bracket,

a mounting clamp pivotally mounted to one side of one ofsaid plates andadapted to cooperate with said semicircularbushing to encircle saidconcentric housing for rotatably= mounting-said hood about said housingand apair of work following rollers, one said roller being attached'to arespective outer side of each said plate and said rollers being incoaxial relation with each other, said rollers being disposed at a pointon said platesproviding for said hood to rotate in a protective positionaround said cutter disc.

2'. In a guard for a rotary saw including a moton a shaft, a concentrichousing attached to said motor and'a cutter disc mounted on said shaft,a seed ada ted to protectively surround a substantialportionofsaidcutter disc, said hood comprising a first semi-circular platehaving an axially disposed semi-circular opening adapted to fit aboutsaid concentric housing, a second semi-circular plate, an arcuatespacing bar adapted to secure said first and second plates in coaxiallyspaced relation, said bar extending around the circumferential edges ofsaid plates to a point wherein there is left an uncovered spacetherebetween, a line of cut viewing member mounted in said uncoveredspace between said plates comprising a substantially U-shaped bracketfastened between said plates and adapted to support a rectangular pieceof transparent material, means rotatably supporting said hood on saidconcentric housing comprising an arm pivotably mounted on the outer sideof said first plate, said arm having an arcuate lower portion adapted tocooperate with said semicircular opening in said first plate to maintain said hood in a' substantially covering position with respect tosaid cutter disc, adjusting means for said amt comprising a bracketsecured to the outer side or-said hood, a wing nut and bolt engaging theupper end of said arm and said bracket and a pair of workfollowingrollers, one each attached to the respective outer side of eachsaidplate and rollers being in coaxial relation with each other.

3'. In a guard for a rotary saw as claimed in claim 2 wherein saidsecond plate is-oftransparent material.

4. In a saw guard for a sawing device including. a motor, a housingconcentric with said motor, a shaft, a circular cutting, disc carried bysaid shaft, and a work supportingv surface below said saw disc, asemi-circular hood adapted to protectively cover a substantial portionof said cutting disc, said hood comprisinga pair of semi circularplaten-first and second spacing members dispdsecl between said platesand adapted to secure said plates in a parallelcoaxial relation,.saidfirst spacing member comprising an arcuate" bar extending along asubstantial distance of the circumferential edges of said plates, saidsecond spacing member comprisingv a bracket secured to the inner. sidesof said plates and disposed forwardly of said first spacing member, atransparent work viewin'g plate secured by said'bracket, there being acoaxial semi:

circular opening. in one of said plates, a semi-circular bearing memberfixed adjacent in coaxial relation, with said semicircular opening,vadjustable means carried by the outer side'of one of said'plates adaptedto cooperate with said semi-circular bearing member to rotatablysecuresaid hood on said concentric housing and a pair of Workfollowing rollerssecured in coaxial relation, one each on a respectivcouter side of saidplates and disposed to roll on:.said work-surface.

References Cited in the file ofthis patent UNITED STATES PATENTS1,240,430 Erickson Sept. 1 s, 1917" 1,375,693 H'owe Apr. 26, 19211,397,606 Smith Nov. 22, 1 9 21 1,589,970 Jones June 22, 1926' 2,669,264Wilson Feb. 16, 1954" FOREIGN PATENTS 599,718 Great Britain Mar.l8';-l-948

